Mort first optioned Simone's life story in 2005 and, at one point, Mary J. Blige had been attached to star. However, the R&B singer ultimately withdrew from the film, reportedly due to production delays.

Nina,which explores the final decade of the singer-songwriter's life and her return to the spotlight after struggles with addiction and her health, co-stars David Oyelowo as Simone's nurse-turned-manager Clifton Henderson.

I've never changed my hair. I've never changed my colour, I have always been proud of myself, and my fans are proud of me for remaining the way I've always been.- Nina Simone

Many objected to the film's casting of the petite, light-skinned Afro-Latina actress as Simone, the outspoken figure who was unapologetic about her dark complexion, natural hair, full lips and wide nose and the artist who penned Four Women, which explores the experiences of black women of different skin tones.

"I've never changed my hair. I've never changed my colour, I have always been proud of myself, and my fans are proud of me for remaining the way I've always been," Simone told an interviewer in one of her most cited quotes.

Nina Simone didn't write Four Women to have her actual skin color demeaned for a movie about her life. Come on now.

Simone's family and estate have also criticized the project, for which they were not consulted. Instead, Simone Kelly, the singer's daughter, participated with filmmaker Liz Garbus for the 2015 Netflix documentary What Happened, Miss Simone? — among Sunday's nominees for best doc feature at the Oscars.

Nina is set for release in all formats — in theatres, digital HD and video-on-demand — on April 22.